1. Field of the Invention
The invention relates to a packing mechanism for achieving a sealed relationship with the bore of a well conduit, which may be employed on packers, bridge plugs, tubing hangers or the like.
2. Summary of the Prior Art
Packers and bridge plugs have long been utilized in the oil and gas well industry to achieve a sealing engagement at a selected position with the bore of a well conduit, such as a casing or a tubing string. Such prior art mechanisms generally incorporate an axially compressible annular sealing unit disposed intermediate an upper slip mechanism and a lower slip mechanism. Conventionally, upward movement of the lower slip mechanism, produced by a mandrel, was transmitted to the annular sealing units and then to the upper slip element to achieve the compression, hence radial expansion of the annular packing element and the setting of the upper and lower slip elements.
This prior art arrangement has the distinct disadvantage in that the upper slip elements are exposed to the well fluids existing in the well conduit above the sealing mechanism. Hence, the upper slips are subject to accumulation of particulates and debris in and around the slip units and the cone for operating the slip units. Such accumulated particulates or other debris can often result in the failure of the upper slip mechanism to properly function.
There is a need, therefore, for a sealing mechanism for use on packers, bridge plugs, or the like wherein an annular packing element is disposed above both the upper and lower slip mechanisms, thus protecting such mechanisms from the deleterious effects of accumulation of particulates and other debris. There is the further need for a bridge plug mechanism that can be utilized below a conventional packer and the combination can be set, then unset and moved to another position in the well without requiring more than one trip into the well.